One of the prior documents that disclose a configuration of a superconducting magnet is Japanese Patent Laying-Open No. 2005-310811 (PTD 1). The superconducting magnet described in PTD 1 includes a coil container containing a superconducting coil and containing liquefied coolant to cool the superconducting coil to a critical point or less, a vacuum container enclosing the coil container for vacuum insulation of the coil container from outside, and an exhaust pipe having one end communicating with the inside of the coil container and the other end lying outside the vacuum container, where the exhaust pipe is provided with a heating means to heat the exhaust pipe, the heating means being provided on at least one area of the exhaust pipe laid inside the vacuum container.